Fluorescent luminaire and mounting arrangement therefor



Oct. 6, 1959 D. w. HARLING FLUORESCENT LUMINAIRE AND. MOUNTINGARRANGEMENT THEREFOR 3 Sheets-Sheet 1 Filed Jan. 28, 1955 INVENTOR.Donald W Har'dng aqttorny D. W. HARLING Oct. 6, 1959 FLUORESCENTLUMINAIRE AND MOUNTING ARRANGEMENT THEREFOR Filed Jan. 28, 1955 3SheetsSheet 2 INVENTOR. DonaZa W. Harlin BY fitzi'arny Oct. 6, 1959 D.w. HARLING ,9

FLUORESCENT LUMINAIRE AND MOUNTING ARRANGEMENT THEREFOR Filed Jan. 28,1955 1 3 Sheets-Sheet 3 Dandid Z 1/.' Hurling BY flttorny United StatesPatent FLUORESCENT LUMINAIRE AND MOUNTING ARRANGEMENT THEREFOR Donald W.Harling, Milwaukee, Wis, assignor to McGraw-Edison Company, acorporation of Delaware Application January 28, 1955, Serial No. 484,8052 Claims. c ams-430) The present invention relates to a fluorescentstreet lighting luminaire, and more particularly to a mountingarrangement and support therefor.

vIn recent years, fluorescent street lighting has become increasinglypopular for the reason that fluorescent luminaries provide a relativelylarge light source with a minimum of brightness or glare. In addition,the power consumption of the fluorescent luminaire is comparatively low.For example, in most installations, each lamp only draws approximately100 watts at a current rating of 1 ampere, with the ballasts onlyconsuming approximately 50 watts. In addition, the cool white color offluorescent lamps will appear to more nearly reproduce actual daylightcolor characteristics .than incandescent lamps or even mercury vaporhigh pressure lamps.

Fluorescent luminaires, in general, do not have a great deal of lateralcontrol of their light pattern, which has been consideredto be somewhatof a disadvantage. However, it ,is generally agreed that surroundingareas adjacent to thelcurb should be illuminated in order to graduallyfade out those areas and to make the background contrast aslittle aspossible for easy accommodation'of the human eye. The spreading lightpattern materially reduces the so-called tunnel effect permitting amotorist driving down the street to see objects, such as cars coming .inoff the side streets or pedestrians appreaching the curb linepreparatory to crossing the street.

Lighting of the surrounding areas gives the driver a ment that isadaptable for use in both street lighting and lighting of general areassuch as shopping-center parking areas and playgrounds and the like wherea nearly circular distribution is desired at the ground level, and withlittle .or no modifications of the mounting structure being required.

Specifically, the present invention provides a means for supportingfluorescent street lighting luminaires in a manner that will permitlight emanating therefrom to provide lateral candlepower distributionclosely approximating accepted standards and specifications. Moreparticularly, thesefstandards are established by the IlluminatingEngineering Society and American Standards Association as recorded 'intheir joint publication entitled. American Standard Practice for Streetand Highway Lighting,

approvedFebruary 27, 1953. The standards, in section 2 j thereof, setforth five recommended lateral distribution a fluorescent streetlighting luminaire mounting arrange- "ice curves prepared from readingstaken in the cone of maximum candlepower. Type IV lateral distributions,as set forth, have a preferred lateral width of 60 degrees with anacceptable range of 50 degrees or wider, and is intended forside-of-road mounting and is generally used for relatively wide roadsand in business districts. Heretofore, fluorescent lighting has beenvery limited in its lateral distribution because of the elongated natureof the light source as compared to an incandescent lamp which issubstantially circular light source controllable by means of refractingprisms in a relatively small outer bowl. It will also be apparent thatan incandescent light source is readily adaptable for ust in type Vlateral distribution, which has a circular symmetry of candlepower atall lateral angles, and which is intended for luminaire mounting at ornear the center of a roadway, in the center islands of parkways, atintersections, and the ever increasing use for parking areas adjacentsuburban shopping centers.

The present invention provides a convenient mounting means adapted tosupport a pair of angularly disposed fluorescent street lightingluminaires to provide desired lateral and vertical light distributionincluding a relatively wide lateral distribution, such as IE8 typeIVdistribution; the invention also includes the provision of a mountingstructure for supporting a third luminaire to provide a nearly circularlateral light distribution such as the IES type V distribution,necessitating little or no modification of the mounting bracket.

Referring now to the drawings:

Fig. 1 is -a top plan view, partly in section, of an installation of afluorescent street lighting structure, with the luminaires illustratedin full lines being arranged for elongated-lateral light distributionand an auxiliary luminaire being shown in dotted lines for installationsrequiring a nearly circular lateral light distribution.

Fig. 2 is a fragmentary side elevational view of the installation withthe various fluorescent luminaires re moved from the mounting supports.

Fig, 3 is an end elevational view taken on lines 3--3 of Fig. 1,illustrating a. preferred fluorescent luminaire to be used with themounting bracket. t

Fig. 4 is an isolux diagram of the comparative light distribution takenat thesame candlepower of three different mounting installations,eachbeing diagrammatically illustrated in the respective Figs. 4a, 4b,,and 40.

Referring now to Figs. 1 and 2, the preferred mounting bracket isgenerally denoted by the reference numeral land is arranged to bemounted on and fastened to a conventional ornamental street lightingstandard 2. In the case of most conventional street lighting standards,

it is preferable to mount the bracket by means of embracing half-bands 3and 4, respectively, which bands are drawn towards embracingrelationship .-by a plurality of mounting bolt and nut assemblies 5. Anangle brace 6 is fastened to the lower portion of the half-band 4 bymeans. of a bolt 7 and to both angular support members and 9,:respectively. The angular support members for strengthreasons arepreferably provided of angle iron or similar material, and are placed inback-to back relationship along one side thereof with the angle brace 6being disposed therebetween by means of athru bolt assembly 10. a

The half-band 4 is preferably provided with "extensions 1'1 projectingfrom its outwardly extendingfiange portions for horizontal support of.therespective angular support. members 8 and 9, which are mountedthereon by means of bolt and nut assemblies 12 received by the elongatedslots 13 in each of the support members. The

slots 13 are elongated to provide for maneuvering the supports intomounting position in caseyof variations in the various cooperatingpieces and/or the standard 2,

An important aspect of the present invention is the configuration of thebracket assembly, which permits the luminaires, denoted generally by thereference numeral 20, to be disposed relative to one another preferablyat an angle of 60 as shown in the diagrammatic view of Fig. 4a. Thus,the angular support members 8 and 9 are each individually formed at anangle of approximately 120 to provide an equilateral triangle defined bythe free ends of the support members when fastened in mounting positionon the pole or standard tube. As shown in Fig. 1, it is preferable toposition the entire luminaire assembly with the curb line passingapproximately centrally of each of the luminaires 20 (shown here in fulllines). This position is also indicated diagrammatically in Fig. 4a andby the full lines in the isolux drawing of Fig. 4. The luminaires areeach provided with two fluorescent lamps indicated in the dotted linesby the reference numerals 21 and 22 of Fig. 3, although more or less ofthe lamps may be positioned in the luminaire if such is desired forlesser or greater intensity. Appropriate reflectors 23 and 24 anddeflectors 25 and '26, nearly coextensive with the longitudinal axis ofthe elongated luminaire, all being illustrated in cross section by thedotted lines in Fig. 3.

The reflector and deflector configuration is more fully described andclaimed in the copending application Serial No. 484,703, filed onJanuary 28, 1955, by Donald W. Harling and assigned to the same assigneeas is the present invention.

It is also to be noted that the present mounting arrangement permits thepole or standard 2 to be positioned substantially at the center ofgravity of the mounting bracket 1, to provide a balanced arrangement forthe luminaires. This is especiallybeneficial for outdoor mounting wherethe relatively long luminaires are subjected to wind and the Weight ofsnow, in addition to the fact that a relatively wider lateral lightdistribution is obtained, approximating the LES type IV distributionwhich includes the 60 angle at the main candlepower beam.

The angular arrangement of the luminaires 20, and especially the 60angle, provides excellent light distribution, approximating the IES type.IV lateral distribution, as may be seen with reference to Figs. 4 and4a. A standard two-way luminaire as shown in the diagram of Fig. 4bprovides an approximately equal light pattern on the street level withopposed halves providing approximately a type I lateral lightdistribution with the added advantage of a relatively greater width. Thearrangement of the present invention provides a light distributionpattern at the street level as shown in the full lines of Fig. 4, andwhich offers the desired background lighting at the house side of thecurb line along with an even greater light distribution on the streetwhere it is most desired. This is done by taking the theoretical 2halves of a two-way luminaire, such as the one illus trated in Fig. 4b,and angularly disposing the halves relative to one another to physicallymove the light pattern outwardly towards the street.

The angle of 60 very nearly approximates the accepted angle at halfmaximum candlepower for the type IV lateral distribution. Anotherimportant feature of the 60 mounting, and especially relating to theequilateral triangular configuration illustrated in Figs. 1 and 4c isthe provision for receiving a third luminaire for purposes of obtaininga light distribution, such as IE8 type V- as indicatedapproximately inthe dotted lines of Fig. 4. This distribution is especially desirablefor commercial and parking lot lighting, which is becoming moreimportant "as suburban shopping centers are being established throughoutthe country. Little or no modification of the mounting bracket "1 isneeded to support the third luminaire, which is shown dotted in Fig. 1and designated generally by the reference numeral 30.

All of the luminaires are preferably supported from the extremities ofthe angular support members 8 and 9 by means of the end brackets 31which are formed substantially identical with one another. The brackets31 are merely a length of strap iron bent angularly at approximately thecenter thereof. Each bracket is preferably fastened in place by means ofnut and bolt assemblies 32 and are positioned in opposed relationshipwith respect to one another for engaging the end castings of theluminaires 20.

Referring now to Fig. 3, the end bracket 31 is shown fastened to the endcasting 33 of the luminaire 20. The luminaire 20, as previouslydescribed, contains the lamps 21 and 22 and appropriate reflectors anddeflectors, and is preferably hermetically sealed by means of a plastictransparent 'cover 34. The cover 34 is preferably hinged at the top (notshown) with reference to Fig. 3 and is secured in place by means of theclamping member 35. An extruded resilient gasket 36 is preferablyprovided to complete the seal and is held in place by the extruded edgemember 37, which is coextensive therewith.

It is also to be noted that the preferred luminaire of Fig. 3 includesmeans for rotating the unit about its longitudinal axis where sodesired. Although, the luminaire has been particularly designed forprojecting light within the accepted range of vertical angles, asdescribed in the aforementioned copending application, Serial No.484,703, the unit may be rotated on its axis to provide variations invertical light distribution. A convenient end-supporting means isprovided for this purpose and includes a pintle pin member 38 rotativelyand pivotally received by the end brackets 31. Fastening machining bolts39 engage threaded apertures in the end casting 33 and are arranged toreceive clamping members, such as the washers 40, for frictionallyengaging the brackets 31 after the lurninaire 20 is adjusted into thedesired mountin=g position. i

It will also be apparent that the luminaire 20 is readily adaptable formounting on a vertical building surface, when light distribution isdesired directly outwardly and downwardly from the luminaire. This typeof lighting is becoming increasingly popular for airport ramp lighting,

whereby the luminaires are mounted directly on the walls of terminalbuildings and hangars (not shown).

It will be apparent that a convenient mounting fixture for fluorescentstreet lighting luminaires has been provided by the present invention,which fixture retains the luminaires in position for wide lateral lightdistribution and also permits mounting of "a third luminaire forapproximately circular distribution which is becoming increasinglypopular for commercial outdoor lighting.

I claim: i 1. In a fluorescent street lighting assembly including firstand second elongated luminaires arranged for elevated mounting on avertical support member, a mounting bracket including fastening meanscomprising clamping half-bands releasably embraceably engageable withsaid support member, and first and second wish-boned configuredangularly disposed luminaire support arms secured to and supported bysaid fastening means, each of the free ends of each of said support armsextending radially outwardly relative to said support member andrespectively defining three included angles of substantially theextremities of said arms including mounting elements for endwisesupporting engagement of said first and second luminaires. 2. In afluorescent street lighting assembly including first and secondelongated luminaires arranged for elevated mounting on a verticalsupport member, a mounting bracket including fa-stening'means comprisingclamping half-bands releasably embraceably engageable with'said supportmember, and a pair of angularly formed luminaire support arms, eachsecured to and supported by said fastening means and each of aconfiguration when mounted intermediate its ends to extend radiallyoutwardly relative to said support member, and each arm References Citedin the file of this patent UNITED STATES PATENTS 1,915,967 Bailey June27, 1933 6 Scott Mar. 26, 1940 Pieper Sept. 24, 1940 Finazzo Sept. 28,1943 Sondahl et al Nov. 4, 1952 FOREIGN PATENTS Great Britain Nov. 5,1931 Great Britain Feb. 25, 1953

